AUTOR: Georgio Kallas TITULO: Practical Riverside Restoration and Bioengineering Guide, Based onWater Purifying Plant Technique Litany River, Lebanon

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TITULO: Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique Litany River, Lebanon

AUTOR: Georgio Kallas

https://www.uco.es/ucopress/index.php/es/

[email protected]

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COTUTELLE DOCTOR AWARD

Programa de Doctorado

BIOCIENCIAS Y CIENCIAS AGROALIMENTARIAS

Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique

Litany River, Lebanon

Guía práctica de restauración y bioingeniería de la ribera, basada en la técnica de una planta purificadora de agua

Litany River, Líbano

Memory presented by

Georgio J. Kallas

To qualify for the degree of Doctor by the University of Córdoba and the Lebanese University The directors of the thesis,

Dr. Rafael Mª Navarro Cerrillo Dr. Guillermo Palacios Rodríguez Full professor

Universidad de Córdoba

Researcher Universidad de Córdoba Dr. Samir Medawar Dr. Salim Kattar Full professor Full professor Lebanese University Lebanese University

Georgio J. Kallas Córdoba (Spain), 17 December 2021

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All rights reserved. The total or partial reproduction of this thesis is not authorized without the prior written permission of the Lebanese University, Doctoral School of Letters and Human and Social Sciences.

© Universidad de Córdoba and the Lebanese University (2021).

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TÍTULO DE LA TESIS: PRACTICAL RIVERSIDE RESTORATION GUIDE.

MODELING GREEN FILTER AND BIOENGINEERING TECHNIQUES: LITANI RIVER, LEBANON

DOCTORANDO: Georgio KALLAS

INFORME RAZONADO DEL/DE LOS DIRECTOR/ES DE LA TESIS

El doctorando presenta y desarrolla en su tesis un trabajo original en el campo de la modelización y la restauración hidrológica, así como el uso de nuevas técnicas para el aprovechamiento y tratamiento de aguas residuales, en entornos bajo riesgo de cambio climático en la cuenca mediterránea. Se trata de un trabajo novedoso, de gran actualidad y demanda en la región donde se desarrolla en estudio, el Líbano, un país bajo grave riesgo de los efectos de cambio climático y cuya gestión del agua supone un importante desafío a resolver dada la enorme dependencia de sector agrícola y forestal de este recurso y la situación crítica esperada bajo los escenarios previstos de cambio climático.

La tesis se centra en la evaluación de la capacidad y aptitud del territorio para la ubicación potencial de nuevos sistemas de tratamiento de aguas residuales basados en bioingeniería, y la modelización hidrológica y el comportamiento de la mayor cuenca hidrográfica del país, la del río Litani, en función de los cambios de uso del suelo y los escenarios futuros esperados de cambio climático, optimistas y pesimistas, con la disponibilidad de recursos hídricos en la zona de estudio. Los procesos de modelización hidrológica desarrollados ofrecen la posibilidad de evaluar la disponibilidad actual y futura de recursos hídricos como herramienta de apoyo a una adecuada planificación territorial sostenible a nivel ambiental, social y económico, así como para el diseño de actuaciones de restauración de las áreas degradas y de tratamiento y reutilización de aguas residuales con fines agronómicos y forestales.

Los resultados presentan interés científico y suponen una novedad en el contexto geográfico en el que se desarrollan, y además son de aplicación en el diseño de actuaciones de restauración hidrológico-forestal y la planificación territorial en zonas semiáridas como el Líbano, donde la falta de información técnica y científica en estos campos suele limitar la capacidad de toma de decisiones y la ejecución de las actuaciones. De este modo, los resultados obtenidos en este trabajo son transferibles a las instituciones encargadas de la gestión territorial, habiendo despartado un gran interés en la Litani River Authority, encargada del diseño y ejecución de actividades restauración hidrológico-forestal, gestión de los recursos hídricos y gestión del territorio ocupado por la cuenca hidrográfica del río Litani.

El desarrollo metodológico es correcto y riguroso tanto en su planteamiento teórico como en su desarrollo posterior, lo cual asegura la validez de los resultados obtenidos, y permite su generalización en posteriores trabajos de investigación. En este sentido cabe destacar la innovación de las técnicas de modelización utilizadas en

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el contexto en el que se realiza la tesis, y su aplicación a un ámbito territorial con elevado interés ambiental y socioeconómico.

El resultado es original en el contexto de la gestión territorial y la evaluación de la capacidad y aptitud de uso de la tierra, como ha sido reconocido con la aceptación con cambios del artículo “Assessment of land suitability for site selection of the biological wastewater treatment system as support of climate change effects mitigation in Lebanon and the Litani River Basin” en la revista indexada Forests (JCR Q1) para su número especial de 2022 sobre Forest Management to Climatic Change.

Como resultado de todo lo anterior consideramos que la tesis objeto de defensa reúne las condiciones formales y científicas para proceder a su presentación.

Por todo ello, se autoriza la presentación de la tesis doctoral.

Córdoba, 17 de diciembre de 2021.

Fdo.: Rafael Mª Navarro Cerrillo Fdo.: Guillermo Palacios Rodríguez

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TITLE OF THE THESIS: PRACTICAL RIVERSIDE RESTORATION GUIDE. MODELING GREEN FILTER AND BIOENGINEERING TECHNIQUES: LITANI RIVER, LEBANON

DOCTORAL CANDIDATE: Georgio KALLAS

REASONED REPORT OF THE THESIS SUPERVISORS

The PhD student presents and develops in his thesis an original work in the field of modelling and hydrological restoration, as well as the use of new techniques for treatment and reclamation of wastewaters in susceptible to climate change environments of the Mediterranean basin. This is a novel work, highly topical and in demand in the region in general and in Lebanon in particular, being a country under serious risk of the effects of climate change. The water management in the country is a major challenge requiring urgent solutions, given the enormous dependence of the agricultural sector on this resource and the critical situation expected under the predicted climate change scenarios.

The thesis focuses on the evaluation of land suitability for the potential installation of new wastewater treatment systems based on bioengineering techniques, and hydrological modelling of the behaviour of the Litani River basin, the largest river in Lebanon. It takes into consideration changes in the land-use and the expected future scenarios of climate change, along with the availability of water resources in the study area. The developed hydrological modelling offers the possibility to evaluate the current and future availability of water resources as a tool to support adequate sustainable territorial planning at environmental, social and economic levels, as well as for the design of actions for the restoration of degraded areas and the treatment and reuse of wastewater for a safer agriculture sector.

The results are pertinent and of valuable scientific interest representing a novelty in the geographical context. They are also applicable to the design of hydrological- forestry restoration actions and territorial planning in semi-arid areas such as Lebanon, where the lack of technical and scientific information in these fields often limits decision- making capacity and the implementation of actions. Thus, the findings of this work are of big interest for the involved Lebanese authorities, namely the Litani River Authority, in charge of the design and execution of reclamation activities, water resources management and management of the Litani River basin and its buffer are.

The chosen methods are correct and based on rigorous literature review. Such meticulous approach ensured the validity of the obtained results, allowing them to be generalised in subsequent research work. In this sense, it is worth highlighting the innovation of the modelling techniques used in the complex context in which the thesis is carried out, in a place of high environmental and socio-economic interest.

The result is original in the context of land management and the assessment of land-use capacity and suitability, as has been recognised with the acceptance of the

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 1

«Rien n'est complet, à tout il manque quelque chose»

-Victor Hugo

«Rien n'est complet, que de l’inachevé… »

-Anonyme

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TO…

MY JAY

… Because One sees clearly only with the heart…

What is essential is invisible to the eye…

Antoine de Saint-Exupéry

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Acknowledgement

As a preamble to this thesis, I would like to extend my sincere thanks to the people who have supported me and who have contributed to the development of this thesis.

These thanks go first of all to the faculty and administrative staff of the University of Córdoba as for the faculty and administrative staff of the Lebanese University, for their efforts to help me as a student.And in particular the Deans Prof. Fawaz el Omar to whom I address all my respect.

I would like to sincerely thank Profs. Dr. Rafael Mª Navarro Cerrillo, Dr. Guillermo Palacios Rodríguez, Dr. Samir Medawar and Dr. Salim Kattar, Thesis Directors, for there guidance and valuable advice, as well as for his patience and perseverance in monitoring this research, and the time they was kind enough to devote to me.

I warmly thank Dr. Guillermo Palacios Rodríguez who left his mark on my research approach, for his faithful comments, his advice and his supervision which allowed me to develop and properly define my research.His immense knowledge and plentiful experience have encouraged me in all the time of my academic research and daily life.

I am extremely grateful to Dr. Salim Kattar, for his invaluable advice, continuous support, and patience during my study. And his daily encouragement to never give up, I can’t thank you enough.

I would also like to thank the Litani River Authory director Dr. Sami Alaouiyeh who, thanks to his authorization, encouraged me to carry out my research and facilitated the data collection and the work in the field. I express my gratitude to the administrative body and members of the Litani River Authory whom I met during the research carried out and who agreed to answer my questions with kindness. Thank you for their availability and their precious testimonials.

Association Philippe Jabre, thank you for your support, can’t achieve it without you…

My Friends, You helped me in my wildest moments, Thank you for being there...

My family, Joseph, Mireille, Joe and Joëlle your love and your support allowed me to get to where I am today. Thank you for your infinite concern, attention and dedication that you have given me over the years.

Special thanks go to my uncle: KALLAS Alain, you could have let the moment pass, or looked the other way, but rather you took the time to occupy yourself ... Thank you every day!Your love and your support allowed me to get to where I am today.

And finally I would like to thank everyone who helped me with this research.

To all these people, I present my thanks, my respect and my gratitude.

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Abstract

In Lebanon, the demand for water resources for domestic, commercial, industrial and agricultural use is increasing dramatically (Jaber, 1997), due to rapid population growth and demographic change (EMWATER, 2004). In southern Lebanon, the Litani River provides a vital water supply.

The river rises west of the city of Baalbek, in the Beqaa valley, and empties into the Mediterranean Sea north of the city of Tire. The Litani River, which stretches for more than 140 kilometers and has an annual flow of 920 million cubic meters, is the longest in Lebanon (LRA, 2010). Climate change and water scarcity are affecting the availability of water for irrigation and agricultural production in a country with the highest number of renewable water resources per unit area in the Middle East (Darwish et al., 2012). Lebanon is a country facing water stress and food insecurity, with more than 7 million people and less than 2 billion m3 of available water (Hamade, 2012), a situation that has been partly generated by a model of use and management of inappropriate territory (Dwarakish and Ganasri, 2015). In this context, an adequate knowledge of the behavior and dynamics of hydrological resources is essential to design an adequate strategy for their management, as well as for land management. For this, hydrological modeling, supported by other remote sensing data sources and managed in GIS environments, are fundamental tools for the development of comprehensive and sustainable management plans for natural resources and land use. In addition, the use of future models and scenarios allows long-term decision-making taking into account the expected environmental conditions as a consequence of climate change, and the design of adaptation and mitigation plans for its effects.

The main objectives of this doctoral thesis have been a) to develop and present a methodological approach and the application of the method of assessing the suitability of land use at the river basin level in a GIS environment to identify the suitability of location of systems of biological wastewater treatment in Lebanon and the Litani river basin region; b) model and analyze the hydrological behavior of the Litani river basin in Lebanon and analyze the effects of land use change on the main hydrological parameters using the WimMed modeling software for the period 2009-2019; c) evaluate the potential impacts of climate change on the hydrological variables of the Litani river basin in Lebanon using the CCSM4 GCM model (Gent et al., 2011) under two of the future scenarios defined by the IPCC (RCP2.6 and RCP8 .5).

In this doctoral thesis, the Litani River Basin (Lebanon) is used as a model hydrological system to link the water-related SDGs (especially SDG 6) with long-term aspects of water management. The objective of this research has been to evaluate water management in the study area and investigate the effects of land use change and climate change on the hydrological variables that define the behavior of the Litani river basin (Lebanon). The first model was evaluated using fuzzy set theory and analytical hierarchy process (AHP) modeling theory in GIS environment, and a suitability mapping for biological wastewater treatment (TBA) in Lebanon was developed, based on specific criteria. The results found that the spatial distribution of the regions eligible for BWWT sites varies based on the criteria, with a total area of 162.94 km2 all over Lebanon and 42.62 km2 in Litani basin areas for these potential locations. These potential sites are selected using land suitability classes in order to preserve the remaining BWWT lands for future generations while mitigating climate change. The model was tested in the field and found to have an overall accuracy of 89%.

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 5 Subsequently, we use the WiMMed hydrological model (Aguilar et al., 2010) to characterize how the change in land use has affected the hydrological parameters in the study area, the Litani river basin, taking the years 2009 as reference years. , 2014 and 2019. The results obtained showed that the change in land use between 2009, 2014 and 2019 had a detrimental impact on the hydrological parameters of this river basin, reducing the infiltration capacity and soil moisture in the second layer. Based on the simulation results, it can be inferred that low differences in runoff were observed at all stations between 2009, 2014 and 2019.

Finally, the current hydrological variables of the study area (infiltration, runoff, soil moisture in the first and second layers) were compared with the variables simulated in 2040 under two future scenarios defined by the IPCC (2008), RCP 2.6 and RCP 8.5, with the assumption that future land use is the same as the current one (2019 land use and cover map). An increase in temperature followed by a decrease in precipitation will lead to a decrease in infiltration, in soil moisture in the second layer in all seasons, and in runoff during spring and winter under the same conditions of use ground. For all stations, all hydrological indicators within the research area are expected to decrease under RCP 8.5 compared to RCP 2.6.

The results of this doctoral thesis indicate that the land use patterns of the study area, the Litani river basin, should be adjusted according to the determined land suitability classes in order to preserve the remaining productive lands, for future generations. This work has been useful to evaluate changes in land use and their influence on the hydrological behavior of the study region, analyzing both what happened in the last decade (2009-2019) and under different future scenarios of climate change in the 2040 horizon. It should also be concluded that in order to suggest restoration activities and reduce the negative effects of land use change and climate change, more detailed studies are needed to define the correct type of land use and design mitigation actions for the effects of climate change in the Litani river basin.

The results of this study provide an important tool to assess the status and hydrological behavior of the Litani River basin in Lebanon. In addition, they can contribute to defining adequate policies and strategies for land use and management, in terms of land use. An adequate territorial planning oriented to productive and sustainable development in this region of Lebanon should consider the influence that possible changes in land use could have on the available water resources. Since the 2009 land capacity map and the one published in this study used essentially the same approach, with different results, they now have the potential to propose a more appropriate adjustment of the centrally established land use strategy on the basis of of large-scale maps. The reduced spatial resolution used in the 2009 classification did not allow the variety of soil characteristics to be considered adequately, which has been corrected in this analysis by significantly increasing the spatial resolution of the analysis for the Litani river basin.

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Resumen

En el Líbano, la demanda de recursos hídricos para uso doméstico, comercial, industrial y agrícola está aumentando drásticamente (Jaber, 1997), debido al rápido crecimiento de la población y al cambio demográfico (EMWATER, 2004). En el sur del Líbano, el río Litani proporciona un suministro vital de agua. El río nace al oeste de la ciudad de Baalbek, en el valle de la Beqaa, y desemboca en el Mar Mediterráneo al norte de la ciudad de Tiro. El río Litani, que se extiende a lo largo de más de 140 kilómetros y tiene un caudal anual de 920 millones de metros cúbicos, es el más largo del Líbano (LRA, 2010). El cambio climático y la escasez de agua están afectando a la disponibilidad de agua para el riego y la producción agrícola en un país que cuenta con el mayor número de recursos hídricos renovables por unidad de superficie de Oriente Medio (Darwish et al., 2012). Líbano es un país que se enfrenta al estrés hídrico y a la inseguridad alimentaria, con más de 7 millones de personas y menos de 2.000 millones de m3 de agua disponible (Hamade, 2012), una situación que ha sido en parte generada por un modelo de uso y gestión del territorio inadecuado (Dwarakish y Ganasri, 2015). Ante este contexto, un adecuado conocimiento del comportamiento y la dinámica de los recursos hidrológicos es fundamental para diseñar una adecuada estrategia de gestión de los mismos, así como de gestión del territorio. Para ello, la modelización hidrológica, apoyada en otras fuentes de datos de sensores remotos y manejada en entornos GIS, son herramientas fundamentales para el desarrollo de planes de gestión integrales y sostenibles de los recursos naturales y del uso del territorio. Además, el uso de modelos y escenarios futuros permite la toma de decisiones a largo plazo teniendo en cuenta las condiciones ambientales esperadas como consecuencia del cambio climático, y el diseño de planes de adaptación y mitigación de sus efectos.

Los principales objetivos de esta tesis doctoral han sido a) desarrollar y presentar un enfoque metodológico y la aplicación del método de evaluación de la idoneidad del uso de la tierra a nivel de cuenca hidrográfica en un entorno SIG para identificar la idoneidad de ubicación de sistemas de tratamiento biológico de aguas residuales en el Líbano y la región de la cuenca del río Litani;

b) modelizar y analizar el comportamiento hidrológico de la cuenca del río Litani en el Líbano y analizar los efectos del cambio de uso de la tierra en los principales parámetros hidrológicos utilizando el software de modelado WimMed para el período 2009-2019; c) evaluar los impactos potenciales del cambio climático sobre las variables hidrológicas de la cuenca del río Litani en Líbano utilizando el modelo CCSM4 GCM (Gent et al., 2011) bajo dos de los escenarios futuros definidos por el IPCC (RCP2.6 y RCP8.5).

En esta tesis doctoral, la cuenca del río Litani (Líbano) se utiliza como sistema hidrológico modelo para vincular los ODS relacionados con el agua (especialmente el ODS 6) con los aspectos de la gestión del agua a largo plazo. El objetivo de esta investigación ha sido evaluar la gestión del agua en la zona de estudio e investigar los efectos del cambio de uso del suelo y del cambio climático en las variables hidrológicas que definen el comportamiento de la cuenca del río Litani (Líbano).

El primer modelo se evaluó utilizando la teoría de los conjuntos difusos y la teoría de modelización del proceso de jerarquía analítica (AHP) en entorno GIS, y se desarrolló una cartografía de idoneidad para el tratamiento biológico de las aguas residuales (TBA) en el Líbano basado en criterios específicos. En los resultados se encontró que la distribución espacial de las regiones elegibles para los emplazamientos de BWWT varía en función de los criterios, con una superficie

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 7 total de 162,94 km2 en todo el Líbano y 42,62 km2 en las zonas de la cuenca del Litani para estas posibles ubicaciones. Estos posibles lugares se seleccionan utilizando clases de idoneidad del terreno con el fin de preservar las tierras restantes de BWWT para las generaciones futuras y, al mismo tiempo, mitigar el cambio climático. El modelo se probó sobre el terreno y resultó tener una precisión global del 89%. Posteriormente, utilizamos el modelo hidrológico WiMMed (Aguilar et al., 2010) para caracterizar cómo el cambio de uso del suelo ha afectado a los parámetros hidrológicos en la zona de estudio, la cuenca del río Litani, tomando como años de referencia los años 2009, 2014 y 2019. Los resultados obtenidos mostraron que el cambio de uso del suelo entre 2009, 2014 y 2019 tuvo un impacto perjudicial en los parámetros hidrológicos de esta cuenca fluvial, reduciendo la capacidad de infiltración y la humedad del suelo en la segunda capa. Basándose en los resultados de la simulación, se puede inferir que se observaron bajas diferencias en la escorrentía en todas las estaciones entre 2009, 2014 y 2019. Por último, las variables hidrológicas actuales de la zona de estudio (infiltración, escorrentía, humedad del suelo en la primera y segunda capa) se compararon con las variables simuladas en 2040 bajo dos escenarios futuros definidos por el IPCC (2008), RCP 2.6 y RCP 8.5, con el supuesto de que el uso futuro del suelo es el mismo que el actual (mapa de uso y cobertura del suelo de 2019). Un aumento de la temperatura seguido de un descenso de las precipitaciones dará lugar a una disminución de la infiltración, de la humedad del suelo en la segunda capa en todas las estaciones y de la escorrentía durante la primavera y el invierno en las mismas condiciones de uso del suelo.

Para todas las estaciones, se prevé que todos los indicadores hidrológicos dentro del área de investigación disminuyan bajo el RCP 8.5 en comparación con el RCP 2.6.

Los resultados de esta tesis doctoral indican que los patrones de uso de la tierra de la zona de estudio, la cuenca hidrográfica del río Litani, deben ajustarse de acuerdo con las clases de idoneidad de la tierra determinadas con el fin de preservar las tierras productivas restantes para las generaciones futuras. Este trabajo ha sido útil para evaluar los cambios en el uso del suelo y su influencia en el comportamiento hidrológico de la región de estudio, analizando tanto lo acontecido en la última década (2009-2019) como bajo diferentes escenarios futuros de cambio climático en el horizonte 2040. También debe concluirse que para sugerir actividades de restauración y reducir los efectos negativos del cambio de uso de la tierra y del cambio climático, se necesitan estudios más detallados para definir el tipo de uso de la tierra correcto y diseñar acciones de mitigación de los efectos del cambio climático en la cuenca del río Litani.

Los resultados de este estudio proporcionan una importante herramienta para evaluar el estado y el comportamiento hidrológico de la cuenca del río Litani en el Líbano. Además, pueden contribuir a definir políticas y estrategias adecuadas de gestión y ordenación del territorio, en cuanto a la utilización del suelo. Una adecuada planificación territorial orientada al desarrollo productivo y sostenible en esta región del Líbano debería considerar la influencia que los posibles cambios en el uso del suelo podrían tener sobre los recursos hídricos disponibles. Dado que el mapa de capacidad de la tierra de 2009 y el publicado en este estudio utilizaron esencialmente el mismo enfoque, con resultados diferentes, ahora tienen el potencial de proponer un ajuste más adecuado de la estrategia de uso de la tierra establecida centralmente sobre la base de mapas a gran escala.

La reducida resolución espacial utilizada en la clasificación de 2009 no permitía considerar la variedad de características del suelo de manera adecuada, lo que se ha corregido en este análisis aumentando de manera importante la resolución espacial del análisis para la cuenca del río Litani.

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Table of figures

Figure 1 Level one and two of the biological wastewater treatment system in Bqaatouta (G. Kallas, 2018) ... 19

Figure 2 Reed unit at time of planting and after several days (G. Kallas, 2018) ... 19

Figure 3 Results and variations of treated wastewater ... 20

Figure 4. Schematic of the biological wastewater treatment system using vertical flow and horizontal subsurface flow (Tilley et al, 2014). ... 32

Figure 5: Litani River Bassin (Shaban, 2011) ... 34

Figure 6. Lebanon maps according to criteria for the application of BWWT ... 45

Figure 7. Litani River Basin maps according to criteria for the application of BWWT ... 47

Figure 8: Potential areas hosting BWWT system according to all criteria ... 48

Figure 9: Potential areas hosting BWWT system according to all criteria ... 50

Figure 10 Litani River Bassin (Shaban, 2011) ... 58

Figure 11. Lebanon main river network ... 60

Figure 12 Digital elevation model of the study area ... 68

Figure 13 A GIS map showing the precipitation in Litani river Basin ... 69

Figure 14 Spatial distribution of the evapotranspiration in 2009, 2014 and 2019. ... 71

Figure 15 Spatial distribution of the average temprature in 2009, 2014 and 2019. ... 73

Figure 16: Soil parameters of the study area: Saturated Hydraulic Conductivity of soil upper layer, Saturated Hydraulic Conductivity of soil second layer ... 75

Figure 17 Soil properties of the study area: Residual moisture, Saturation moisture, Thickness of soil upper layer and Thickness of soil second layer ... 77

Figure 18 A GIS map of the study area showing the lower Litani watershed (USAID, 2013)... 78

Figure 19 Geological Map of the Upper Litani Basin (USAID, 2013) ... 79

Figure 20 Cross sections showing the extent of the formations in the Subsurface (USAID, 2013) ... 80

Figure 21 A GIS map showing the Geology in Litani river ... 80

Figure 22: Spatial distribution of the Soil Moisture of the first Layer depending on the season in 2009, 2014 and 2019. ... 85

Figure 23 Spatial distribution of the Soil Moisture of the Second Layer depending on the season in 2009, 2014 and 2019. ... 87

Figure 24 Spatial distribution of the Rainfall in 2009, 2014 and 2019. ... 89

Figure 25 . Spatial distribution of the Snowfall in 2009, 2014 and 2019. ... 91

Figure 26 Land cover map of Litani River basin in 2009, 2014 and 2019. ... 94

Figure 27 Litani River Bassin (Shaban, 2011) ... 104

Figure 28 Lebanon main river network ... 106

Figure 29 A GIS map showing the precipitation in Litani river Basin in 2019 ... 109

Figure 30 Simulation of total rainfall and evapotranspiration for scenarios RCP2.6 and RCP8.5 (from left to right) in the study area ... 110

Figure 31: Simulation of total infiltration for scenarios RCP2.6 and RCP8.5 respectively... 111

Figure 32: Simulation of total runoff for scenarios RCP2.6 and RCP8.5 respectively ... 112

Figure 33: Simulation of total soil moisture layer 1 and 2 for scenarios RCP2.6 and RCP8.5 respectively ... 113

Figure 34: Simulation of total snowfall for scenarios RCP2.6 and RCP8.5 respectively. ... 115

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Figure 35: Simulation of temperature for scenarios RCP2.6 and RCP8.5 respectively ... 116

Figure 36 Potential areas hosting BWWT according to precipitation criteria119 Figure 37 Potential areas hosting BWWT according to precipitation criteria and RCP 2.6 and RCP 8.5 scenarios ... 119

Figure 38 Potential areas hosting BWWT according to all criteria ... 123

Figure 39 Potential areas hosting BWWT referring to RCP 2.6 and RCP 8.5 scenarios ... 124

Table of tables

Table 1: Concentrations of various parameters collected ... 20

Table 2: Characteristics and total quantity of domestic and commercial wastewater for the entire Lebanon (CDR, 2001). ... 26

Table 3: Annual available resources (Million cubic meters) (MoE/LEDO/ECODIT, 2001). ... 29

Table 4: Estimated water consumption and projected water demand in Lebanon for 2015-2030 (El Moujabber et al, 2006) ... 29

Table 5: The comparison scale in AHP (Saaty, 2008) ... 32

Table 6: The comparison scale in AHP of each selected criterion ... 37

Table 7: Soil erosion, depth and type according to their suitability in BWWT ... 39

Table 8: Fuzzy set memberships, membership functions and areas used for BWWT system in Lebanon... 41

Table 9: Fuzzy set memberships, membership functions and areas used for BWWT plants in Litani River Basin ... 42

Table 10 Weather stations in Litani River Basin ... 63

Table 11 Ranges of saturated hydraulic conductivity (Ksat) and porosity for the USDA soil textural classes (Saxton & Rawls, 2009) ... 64

Table 12 Van Genuchten parameter (n) including residual (Θr) and saturated (Θs) water content compiled from the UNSODA database (Leij et al., 1996). ... 65

Table 13 Thickness of upper layer 1 and lower layer 2 from the Soil Map of Lebanon at 1:50,000 scale database (Darwish, 2006). ... 66

Table 14 Calibration parameters used in WiMMed. ... 67

Table 15 Average data of evapotranspiration for 2009, 2014 and 2019 in the study area ... 70

Table 16 Average data of temperature for 2009, 2014 and 2019 in the study area ... 72

Table 17 Lithological characteristics of the Litani Lower watershed (Doummar et al, 2009) ... 78

Table 18 Average data of Infiltration (mm) by season for 2009, 2014 and 2019 in the study area. ... 82

Table 19 Average data of Runoff (mm) by season for 2009, 2014 and 2019 in the study area. .. 82

Table 20 Average data of Soil Moisture of the Second Layer (mm) by season for 2009, 2014 and 2019 in the study area. ... 83

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Table 21 Average data of Soil Moisture of the Second Layer (mm) by season for 2009, 2014 and 2019 in the study area. ... 83

Table 22 Average data of rainfall for 2009, 2014 and 2019 in the study area ... 87

Table 23 Average data of snowfall for 2009, 2014 and 2019 in the study area ... 88

Table 24 Land cover change in Litani River watershed for the period 2009- 2014 – 2019. ... 93

Table 25 Effects of climate change ... 102

Table 26 Calibration parameters used in WIMMED. ... 107

Table 27 Hydrological behavior of the study area in autumn under control year and climatic change scenarios ... 111

Table 28 Hydrological behavior of the study area in spring under control year and climatic change scenarios ... 112

Table 29. Hydrological behavior of the study area in summer under control year and climatic change scenarios ... 114

Table 30 Hydrological behavior of the study area in winter under control year and climatic change scenarios ... 114

Table 31 Fuzzy set memberships, membership functions and areas used for BWWT systems in Litani River Basin ... 120

Table 32 . Soil erosion, depth and type according to their suitability in BWWT ... 121

Table 33 Fuzzy set memberships, membership functions and areas used for BWWT system in Litani River Basin ... 124

Table 34 River restoration scenarios based on five ecosystem amenities that commonly motivate restoration projects ... 125

Table 35: Example of biological river side restoration techniques that could be applied in our case study area ... 129

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1 Chapter Introduction

Climate Change is the defining issue of our time and we are at a defining moment. From shifting weather patterns that threaten food production, to rising sea levels that increase the risk of catastrophic flooding, the impacts of climate change are global in scope and unprecedented in scale. Without drastic action today, adapting to these impacts in the future will be more difficult and costly (UN, 2020). It refers to significant, long-term changes in the global climate (Keyman et al, 2011). More frequent droughts and shifting precipitation patterns lower water levels in rivers, lakes and streams, leaving less water to dilute pollutants. Higher temperatures cause more frequent algal blooms and reduce dissolved oxygen levels, both of which can cause fish kills and do significant harm to ecosystems (American Rivers, 2021). Riverine ecosystems are particularly vulnerable to climate change because: (1) Many species within these habitats have limited dispersal abilities as the environment changes; (2) Water temperature and availability are climate- dependent; and (3) Many systems are already exposed to numerous anthropogenic activities pressures (Woodward et al. 2010).

During the 21st century, the average global temperature is projected to increase by 1.8–4.0 °C by 2050 (IPCC 2007a). Increases in surface air temperature associated with climate change will vary seasonally and will be greater in some regions than others thus more strongly affecting rivers (Rosenzweig et al, 2008). Because streams and rivers are generally well mixed and turbulent, they respond to changes in atmospheric conditions easily and thus they will become warmer (Eaton and Scheller 1996; Kaushal et al, 2009). At higher latitudes temperature changes will be pronounced as will changes in discharge due to earlier snowmelt (Milner et al, 2009). Little or only small changes in total annual precipitation are expected in many Lebanese regions; however, the distribution of that rain throughout the year will likely vary.

Another important, human-induced impact that directly affects water temperature and thermal regimes is deforestation and removal of riparian vegetation. The removal of riparian vegetation can have tremendous effects on water temperatures as increased energy input from radiation induces heating. Small streams with lower heat capacity are quite vulnerable to this impact, especially where a full canopy of riparian vegetation naturally occurs. Stakeholders, decision- makers, local councillors, governors and planners must rethink how they can maintain high levels

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 14 of agricultural food production while also maintaining good drinking water quality, limiting greenhouse gas emissions, and safeguarding the social and economic benefits of their landscapes (Brown et al., 2008). Land capability evaluation is critical for managing land resources because it tells us whether the resources are degraded or improved in quality (Girmay et al., 2018). Land capability classification systems define and communicate biophysical land use constraints such as climate, soils, and topography. As a result, they can provide an accessible format for both scientists and decision-makers to share knowledge about the effects of climate change and adaptation (Brown et al., 2011). Land suitability based on capability at the region level would assist decision- makers in identifying different soil types in accordance with their suitability for sustainable soil fertility management. The agricultural land suitability map could provide a general orientation on how to best use the soil to increase land productivity and mitigate the effects of climate change.

Therefore, achieving sustainable land use is the first step toward adapting to climate change and mitigating its effects. As a result, a current assessment of land characteristics is required. In general, the water sector (hydrosphere) comes after the land sector (lithosphere). Water is an essential component of human activities, influencing the expansion of human communities and the development of local economies across landscapes (Hartter et al., 2018). Hydrological modeling is one method that will play an important role in mitigating the effects of climate change and in providing early warning of climate disasters. For over 40 years, modeling methods have been widely used for a variety of purposes, but almost all modeling tools have been primarily developed for humid area applications (Wheater et al., 2008). Despite the critical importance of water in riparian areas (lands that occur along watercourses and water bodies, typical examples include flood plains and streambanks. They are distinctly different from surrounding lands because of unique soil and vegetation characteristics that are strongly influenced by the presence of water.), hydrological data in Lebanon, especially in the litany river basin region has traditionally been severely limited. The lack of high-quality observations has been widely cited as a major constraint to the development of riparian-zone hydrology (Pilgrim et al., 1988).

Hydrological modeling and the necessary supporting data are critical for developing riparian zones and areas that are typically stressed by environmental factors. Various parameters needed for modeling will be derived from remote sensing data, such as a digital elevation model (DEM), drainage and permeability data of the soil, soil type and depth map, soil erosion and land degradation level/rate/vulnerability map and so on. Scientists have recently turned to satellites to

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 15 find this vital flow data (Gleason et al., 2018). Remote sensing approaches and methods are critical tools for guiding spatial planning. Satellite remote sensing provides a systematic, synoptic framework for advancing scientific knowledge of the Earth as a complex system of geophysical phenomena that frequently result in natural hazards, both directly and through interacting processes. Improved and integrated measurements, combined with numerical modeling, are allowing for a better understanding of where and when a specific hazard event is most likely to occur and have a significant socioeconomic impact. Accurate modeling will necessitate estimating the spatial and temporal distribution of water resource parameters. Engineers and planners have shown a growing interest in using Geographic Information System (GIS) and satellite-based remote sensing (RS) technologies to extract land surface parameters, which existed as a threshold in the early days to approach reasonable results in hydrological modeling. GIS and RS have become efficient tools for integrating spatial and non-spatial databases for hydrological modeling as computer technology has advanced (Gandodagamage, 2001).

Due to rapid population growth and demographic change (EMWATER, 2004) the demand for water resources for domestic, commercial, industrial, agricultural and aesthetic-touristic use in Lebanon is skyrocketing (Jaber, 1997). The Litani River is an important source of water in Lebanon. The river rises west of Baalbek in the fertile Beqaa Valley and flows into the Mediterranean Sea north of Tyre (South of Lebanon). The Litani River, which stretches for more than 140 kilometers and has an annual flow of 920 million cubic meters, is Lebanon's longest river (LRA, technical report, 2010). Climate change and water scarcity are affecting water availability for irrigation and agricultural output in a country with the most renewable water resources per unit area in the Middle East. According to the annual precipitation map, the Litani River falls under two main rainfall ranges. In its upper sections, the Litani area receives 1,100 to 1,200 mm of rain per year, while its lower section receives 800 mm of rainfall per year (Atlas Climatique du Liban, 1969). Precipitation ranges varies between 1000-1400 mm with an area of 2809.8 km², 700-1000 mm with an area of 3695.92 km², 400-700 mm with an area of 2405.1 km² and 300-400 mm with an area of 479.1 km². The evaporation coefficient from the Litani River is estimated to reach 68.2%

because of the dry nature of the climate in southern Bekaa and in the south. This value is probably less significant during wintertime. The coefficient of infiltration of rainfall water from the Litani watershed into the aquifers formations and other basins varies according to the nature of the geological formations and the faulting system (UNDP 1970). The seepage from the Litani

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 16 Riverbed into the ground water was estimated at 22% (UNDP 1970). As indicated by the Litani Water Authority, in terms of recharge, most of the wells do not belong to the Litani Watershed and are being used for domestic consumption with approximate yields ranging between 2000 and 4000 m³/day (FAO 1970).

The general objective of this work is to present a methodological approach and application of land suitability assessment method which is designed for use at a small catchment level, in a GIS environment to find the best land suitability for a biological wastewater treatment system in Lebanon and the Litani River Basin region. As studying the hydrological behavior of Litani River Basin in Lebanon and analyzing effects of land use change on soil moisture using the WIMMED modeling software for the period 2009-2019. Equally it has the objective to assess the potential impacts of climate change on hydrological variables of the Lebanese part of Litani river basin using CCSM4 GCM model (Gent et al., 2011) under 2 representative concentration pathways (RCP2.6 and RCP8.5). The achievement of this general objective was developed in the following specific objectives:

 Assessing potential areas that can host biological wastewater treatment systems according to criteria: land use, soil components (erosion, depth, and type), precipitation, population number, and slope.

 For ten years, 2009 and 2019, a distributed physically-based watershed model (WiMMed) was used in the Litani River Basin.

 Using this model, generating the hydrological variables that characterize the water balance in the unsaturated zone of the soil in the study region between 2009 and 2019.

 Comparing the land use maps from the two years and identifying the changes in land use in terms of type and area of change.

 Investigating the link between soil moisture measurements and land use changes in the Litani River Basin between 2009 and 2019.

 Drawing inferences on how changes in land usage may affect the second layer's soil moisture in a riparian area.

 Generating the hydrological variables (infiltration, run-off and soil moisture of second layer) of Litani river basin using WIMMED model and the current climatic conditions as inputs.

 Perturbing the historical time series of climatic data according to RCP2.6 and RCP8.5 scenarios.

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 Simulating the hydrological characteristics of our study area under the perturbed climate using the calibrated hydrological model.

 Comparing the model simulations of the current and possible future hydrological characteristics.

 Drawing conclusions on how climate change would affect hydrological characteristics in a Lebanese riparian area.

Lebanon's goal is to develop its land resources while maintaining an ecological balance and conserving the diverse biological resources found there. Combating land degradation is at the heart of this country's environmental programs. Integrate remote sensing data with several other data types into a GIS is used for this purpose to develop various models for monitoring and exploring land surface changes and degradation, as well as for producing dynamic information, because satellites can cover vast and inaccessible areas and provide long-term repetitive data. Some studies in Lebanon used remote sensing techniques as a tool for assessing and managing land degradation;

but we couldn’t find studies use remote sensing techniques as a tool for assessing wastewater treatment system in Lebanon or in Litani River Basin specifically. Some applications and studies related to the study area (Litani river basin area) are listed below:

 Litani river basin management support program by USAID focusing on feasibility study for constructed wetlands in the Litani river basin.

 State of Art about water uses and wastewater management in Lebanon showing the real situation about management of water and wastewater in Lebanon and focusing on problems related to urban water pollution released in environment.

 Restructuring water sector in Lebanon: Litani river authority facing the challenges of good water governance targeting the agricultural research, the rural development, studies and construction of dams and irrigation projects, the management of hydrometric gauge stations on all the Lebanese rivers, the monitoring and the prevention of pollution.

 Water Demand Management in Some Arab Countries Using GIS to show how Geographical Information Systems (GIS) can be used to support infrastructure planners and analyst on water demand of a local area in some Arabs countries.

After reviewing existing knowledge on the application of remote sensing and hydrological modeling in land management in Lebanon, it is discovered that this field is understudied. Climate change-related maps and future scenarios continue to be lacking. This study focuses on the use of

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 18 remote sensing and the application of a hydrological model (WiMMed) to mitigate the effects of climate change in Lebanon (case study: Litani River Basin). Climate change mitigation refers to efforts to reduce or prevent greenhouse gas emissions. Mitigation can take the form of implementing new technologies and renewable energies, upgrading older equipment to be more energy efficient, or altering management practices or consumer behavior. Mitigation also includes preserving forests, watercourses, and lands, as well as researching soil capacity.

Land suitability is defined as the ability to accept a specific type and intensity of land use indefinitely or for a specified period of time under certain management conditions without long- term degradation (Houghton & Charman, 1986). If you understand and respect the capabilities of each land, you can reduce the risk of soil damage while also contributing to climate change mitigation and assisting countries in transitioning to a low-carbon society. Mapping land suitability at the district level in a spatial and timely manner can provide a tool for conserving and managing natural resources, thereby reducing the negative effects of climate change. We will present a validated modeling procedure for assessing land suitability using available soil information and a DEM for the Litani River Basin to map land suitability.

The importance of assessing the land suitability and the potential areas hosting biological wastewater treatment system in the development and preservation of the environment, health and water sources, as well as a solution for treated water able to be used in irrigation was emerged after having the clear results of BOD and COD levels from the wastewater treatment system applied in Bqaatouta Lebanon. Bqaatouta’s biological wastewater treatment system is characterized by low costs and low energy consumption. It is also known for its environmental ways in treating domestic, industrial and agricultural liquid wastes. The whole biological system lies on a surface of 3 000 m², divided into 2 levels: the first one using the vertical system on a surface of 900 m² and is feeded by wastewater through 6 estuaries, and the second level using the horizontal system on 2 000 m² and is feeded by wastewater from level 1 through 2 estuaries (Fig.1, Fig. 2 and Fig.

3).

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 19 Figure 1 Level one and two of the biological wastewater treatment system in Bqaatouta (G. Kallas, 2018)

Figure 2 Reed unit at time of planting and after several days (G. Kallas, 2018)

After the wastewater comes out from the whole system (2 levels vertical and horizontal system) with a clear color without any odor or any harmful effects, it is tested. We advise that like these solutions should be spread over many medium-sized villages. Samples are analyzed in professional laboratories with the collaboration of the Lebanese University faculty of Agriculture. Results are shown in the table 1 and figure 3.

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 20 Table 1: Concentrations of various parameters collected

Parameters

Samples

1 2 3 Acceptable

Average for irrigation use of water (FAO, 2010) Biological Oxygen Demand

(BOD) mg/l

73 Less than 5 mg/l Less than 5 mg/l 25 Chemical Oxygen Demand

(COD) mg/l

182 Less than 30 mg/l Less than 30 mg/l 125

Ph 8.5 8.4 8.4 6.5-8.5

Total Phosphorus mg/l 9.1 6.4 0.7 8

Total Suspended Solids (TSS) mg/l

102 21 8 60

Total Kjeldahl Nitrogen mg/l 55 41 15 34

Total dissolved solids (TDS) mg/l

665 663 640 829

Sulfide mg/l Less than 0.05 mg/l

Less than 0.05 mg/l

-

Chloride mg/l 57 78 82 -

Total coliforms (MPN/100ml) ˃2.4 x 10³ ˃2.4 x 10³ ˃2.4 x 10³ ˂200

E.coli (MPN/100ml) ˂1 ˂1 ˂1 -

Figure 3 Results and variations of treated wastewater

73

5 5

182

30 30

9.1 6.4

0.7 102

21

8 55

41

15

0.05 0.05 0.05

57

78 82

0 20 40 60 80 100 120 140 160 180 200

sample 1 sample 2 sample 3

Values of treated waste water

BOD COD TP TSS TN S C

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 21 The results show that the quality of water after treatment is better than the acceptable average for irrigation. So, this treated water can be used to irrigate the landscape with public access (parks, lawns, golf courses...) and crops slightly according to the Acceptable Average for irrigation use of water (FAO, 2010). After several years of studies in worldwide countries, the biological wastewater treatment plant showed a large improvement in the domain of filtered wastewater. This system is implemented in “Bqaatouta” as a solution for the water crisis in Lebanon and the treatment of wastewater in rural and urban areas. This system is thus a successful system since it decreases the impact of pollution on the rivers and sea borders by 40%. The vertical and horizontal systems both work on the reduction of physicochemical pollutant parameters such as total phosphorus, total suspended solids, total nitrogen and total dissolved solids. Biological wastewater treatment is well recommended in Lebanon especially in the rural areas where large lands are available.

Changes in land use in a watershed can influence water quality and supply (Turner et al., 2001).

As a result, assessing land use patterns and changes at the Litani river basin level is critical to water resource and land use planning and management in a watershed (Butt et al., 2015). The state of land cover/land use in Lebanon has been marked by constant change over the last few decades. A lack of land management plans and/or proper urban restrictions has severely harmed both the natural and built environments. As a result, uncontrolled urban sprawl at the expense of natural environments has been facilitated (MoE & UNDP, 2011).

In this study, an attempt was made to compare the current hydrological variables of the study area using WIMMED hydrological model (infiltration, run-off, second-layer soil moisture) to the simulated variables in 2050 under two RCP scenarios: RCP 2.6 and RCP 8.5, assuming that future land use is the same as current land use (2019 land use/land cover map). Seasonal variations of hydrological variables (infiltration, runoff, and soil moisture of second layer) due to future climate change were observed because the study region has highly variable precipitation for each season due to the existence of four seasons and the influence of topographical variation. Changes in climate under representative concentration pathways (RCP) scenarios affect infiltration, run-off, and soil moisture in the second layer of the Litani river basin in Lebanon. Changes in mean and total infiltration, run-off, and soil moisture of the second layer were calculated for the years 2013- 2040 using the RCP 2.6 and 8.5 scenarios. The findings show that climate change affects all these

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 22 variables, albeit at varying rates. As a result, the river basin will almost certainly be subjected to a variety of negative consequences. Where both RCP 2.6 and 8.5 demonstrated decreases in the mean values of infiltration, run-off, and soil moisture of the second layer across all seasons when compared to current values of these hydrological parameters. The findings of this study are required to forecast the spatiotemporal variability of hydrological parameters in order to design policies for long-term water resource development. And help to mitigate the negative consequences of climate change, such as extreme drought or flooding.

As a result, the following are the general and particular aims of each chapter of this thesis:

I. The general goal of the first half of this study (Chapter 2) was to offer a methodological approach and implementation of a land capability assessment method developed for usage at a local catchment level for biological wastewater system locations, utilizing readily accessible soil data and the DEM.

II. The basic goal of the second section (Chapter 3) was to investigate the link between the hydrological variables involved in water balance at a watershed scale and land use change in Lebanon's Litani river basin between 2009 and 2019. The following particular objectives were created to help attain this broad goal:

 Using a distributed physically based watershed model (WiMMed) in the Litani river basin for 10 years, 2009 and 2019.

 Using this model, generating the hydrological variables that characterize the water balance in the unsaturated zone of the soil in the research region between 2009 and 2019.

 Comparing the land use maps from both years and finding changes in land use in terms of type and area of change.

 Investigating the link between the hydrological variables acquired and land use changes in the Litani river basin between 2009 and 2019.

 Drawing inferences on how changes in land use will affect soil moisture in the second layer in a Lebanese riparian area.

III. The overall goal of the final section of the research (Chapter 4) was to analyze the possible implications of climate change on hydrological variables and the biological wastewater treatment system locations in the Lebanese part of Litani river basin using the CCSM4 GCM model (Gent et al., 2011) and two typical concentration routes

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Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique: Litany River, Lebanon - Georgio Kallas 23 (RCP2.6 and RCP8.5). The following particular objectives were created to help attain this broad goal:

 Using the WiMMed model and current climatic conditions as inputs, generate the hydrological variables (infiltration, run-off, and soil moisture of the second layer) of the Litani river basin.

 Projecting present climatic data according to RCP2.6 and RCP8.5 scenarios in order to use the WiMMed hydrological model to replicate the hydrological features of our research region under the predicted climate.

 Contrasting model simulations of existing and potential future hydrological features.

 Making predictions about how climate change may alter hydrological parameters in a Lebanese riparian area.

IV. Finally, to consolidate all of the material obtained in this thesis, a General Discussion (Chapter 5) and General Conclusions (Chapter 6) will be offered.

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2 Chapter Assessing land suitability for biological wastewater treatment system option in Lebanon and Litani River Basin, using an integrated GIS- based decision support system.

Abstract: : This paper presents a validated model to map land suitability for biological wastewater treat-ment systems under the climatic conditions of Lebanon and the Litani River basin, using a Geo-graphic Information System (GIS) and the available information and criteria (land use, soil components, precipitation, population number, and slope) for the Litani River Basin and Leba- non. The model was validated using fuzzy set theory and the analytic hierarchy process (AHP) modeling theory, and a final suitability map was created in Lebanon that combined potential areas for Biological Wastewater Treatment (BWWT) based on particular criteria. The study shows that spatial distribution of the suitable areas for BWWT sites differs for each of the criteria and the total area of these potential areas is 42.62 162.94 km2 allover Lebanon and 42.62 km2 in Litani basin areas. This area covers around 1.55% of Lebanese areas and can help more than 30 regions and the total number of beneficiaries can reach by a minimum 60000 and a maximum of 180000 which represent between 1.5% and 3.75% of the total population. These potential areas are identified through land suitability classes to sustain the remaining BWWT areas for future generations and can mitigate the impact of climate change.

Key words: Land suitability; Biological wastewater treatment; Geographic Information System;

Litani River Basin; Lebanon.

AUTOR: Georgio Kallas TITULO: Practical Riverside Restoration and Bioengineering Guide, Based onWater Purifying Plant Technique Litany River, Lebanon

TITULO: Practical Riverside Restoration and Bioengineering Guide, Based on Water Purifying Plant Technique Litany River, Lebanon